At least 13 people were killed in a conflict between Christians and Muslims in Cairo, reported Egypt’s state-run TV station on Wednesday.

Another 90 people were injured in the clashes. The sectarian violence occurred after hundreds of Coptic Christians held a protest Tuesday near the Egyptian TV Building to demonstrate against the burning of St. Mina and St. George church in Soul, 18 miles south of Cairo, this past Saturday.

A Muslim mob had reportedly burned the church over the weekend after villagers discovered that a local Christian man was in a romantic relationship with a Muslim woman.

On Tuesday, about 500 Coptic protesters from Manshier Nasr, also known as “Garbage City,” were on their way to join the protest at the Egyptian TV Building regarding the burnt church when they were met by thousands of Muslims from the nearby area of Sayeda Aisha and Mokattam. The Muslims were reportedly armed with weapons and automatic guns, according to Assyrian International news Agency (AINA).

In the beginning, stones were thrown at the Coptic protesters. Later, however, Molotov Cocktails were hurled at them.

Eventually, the military arrived at the scene of the conflict and reportedly only stood and watched initially. Then they fired in the air and eventually fired live ammunition at the Coptic side, according AINA based on reports from Coptic eyewitnesses.

“We were at one side and the Muslim on the other, we have hundreds of injured at the Coptic side,” said an eyewitness. “The Muslims were also shooting from behind the army tanks.”

Attorney Wagih Anwar Abou Saad, who also witnessed the conflict, told Free Coptic Voice that, “the army is protecting the Muslims, who sought shelter behind the army tanks.”

Father Abdelmaseeh Baseet of the Coptic Church on Wednesday said all those killed in the clash were Christians, according to CNN.

The Egyptian military, which has taken control of the country after the ousting of President Hosni Mubarak, vowed to investigate who is behind “the acts of violence” and to hold them accountable “to the full extent of the law.”

Besides the human toll, the clash also resulted in eight homes and 20 garbage recycling factories, owned by Copts, torched. About 30 garbage collection vehicles were also burned.

The outbreak of violence on Tuesday is the latest in a string of Christian-Muslim conflicts this year in Egypt. On New Year’s Eve, 21 people were killed by a suicide bomber outside of a Coptic church in Alexandria. The explosion wounded about a hundred people.

Then less than two weeks later, a gunman fatally shot a Christian man and wounded five other Copts on a train in Egypt.

And in late February, a monk and six church workers were shot and wounded when the Egyptian Army attacked a Coptic Orthodox monastery in Wadi Al-Natroun, 68 miles north of Cairo.

Since Saturday, when the Soul church was burned, Copts have been sitting in front of the Egyptian TV building to protest against the army’s failure to hand over the church building in Soul as it had promised.

Somewhere between eight to 12 percent of Egypt’s population of 80 million people is Christian.